Life is made up of three parts- in The First Third, you're embarrassed by your family; in the second, you make a family of your own; and in the end, you just embarrass the family you've made.
That's how Billy's grandmother explains it, anyway. She's given him her bucket list (cue embarrassment), and now, it's his job to glue their family back together.
No pressure or anything.
Fixing his family's not going to be easy and Billy's not ready for change. But as he soon discovers, the first third has to end some time. And then what?
It's a Greek tragedy waiting to happen.